The main examination of Mycobacterium tuberculosis is pathogenic examination. 1. smear microscopy, which can be performed by smear examination of various secretions and excretions such as sputum, urine, pleural fluid, feces and lymph node puncture fluid. If antacid bacilli can be detected, it is positive, but the rate of positivity is relatively low. sputum smear negative cannot exclude tuberculosis, and must be examined more than or equal to three times in a row to improve the detection rate. 2. culture of pathogenic bacteria, take the corresponding specimen for culture of Mycobacterium tuberculosis, this isolated culture method is more specific than the smear method, and is also an important diagnostic criterion for identifying non-tuberculous mycobacteria. 3. genetic testing method: The corresponding samples are obtained through endoscopy, such as bronchoscopy, thoracoscopy, laparoscopy, etc., and genetic testing of Mycobacterium tuberculosis is performed, such as common PCR methods, X-pert testing, and genetic macrogenetic sequencing methods.